1. Field of the Invention
This invention relates to fatty amide derivatives. More particularly, this invention relates to novel polyether amide derivatives derived from water-soluble polyether amines and fatty acids and especially to their use as viscosity enhancing agents in liquid cleaning compositions. Excellent properties are exhibited with these products and compositions are provided which should be useful in a number of applications such as liquid skin cleansers, liquid soaps, liquid laundry detergents, and blends of nonionic, anionic, and/or cationic surfactants or nonionic surfactants alone.
The polyether amides of this invention are prepared by reacting equivalent amounts of water-soluble polyether amines with fatty acids. Suitable fatty acids include those which are common, inexpensive and fairly easy to obtain, such as oleic, tallow, tall and coconut. The reaction to produce the polyether amides is preferably conducted under vacuum at a temperature within the range of about 100.degree. C. to about 300.degree. C. and preferably above 150.degree. C.
2. Description of the Related Art
There are a variety of methods known to thicken compositions containing anionic surfactants. See Surfactants in Cosmetics, Vol. 16 of Surfactant Science Series, M. M. Rieger, Ed., Marcel Dekker 1985, Chap. 9, pp. 251-292, for a discussion of related topics.
Articles by P. Alexander on "Rheological Additives" in Mfg. Chemist and Aersol News, May 1986, p. 71 and June 1986, p. 49 provide a good overview of many of the rheological materials available to affect viscosity in personal care products. These materials include inorganic thickening agents, various mineral and clay substances, mastergels, synthetic materials which have improved characteristics over swelling clays, gel systems, pyrogenic silicas, polar and non-polar media and other silicas.
An overview of the chemistry of detergent-softener formulations containing a nonionic detergent and cationic fabric softener, and optional ingredients can be found in the Sherex Technical Bulletin "Formulating Liquid Detergent-Softeners" (1983).
Other possible formulations for nonionic detergents, fabric softeners and optional ingredients can be reviewed in Armak Technical Bulletin No. 82-16 "Formulating Liquid Detergent/Softener/Antistatic Products with Armosoft.RTM. WA Bases" (1982).
Some aspects of detergent properties of nonionic and cationic surfactant formulations are presented in Texaco Chemical Company Technical Applications Bulletin (1984) "Liquid Detergent-Softener Formulations With Surfonic.RTM. N Nonionic Surfactants"
U.S. Pat. No. 3,954,660 to Kennedy, et al. proposes increasing the viscosity of anionic surfactant slurries by admixing with such slurries an effective amount of an additive selected from the group consisting of dialkyl ethers, alkoxyethoxyethanols and tertiary amines having the general formula R.sub.3 N, wherein R is an alkyl group containing from 2 to 4 carbon atoms.
Polymeric thickeners are known to capitalize on the hydration and swelling properties of high molecular weight polymers and the chain extension and hydrogen-bonding of polymer units to achieve an increase in viscosity. European Pat. Nos. 132,961 and 133,345 disclose liquid soap compositions containing a water-soluble polymer selected from the group consisting of hydroxyethyl cellulose and hydroxypropyl guar. A quaternary nitrogen-containing cellulose ether thickening agent is disclosed as useful in the production of mild thickened liquid shampoo compositions in U.S. Pat. No. 3,962,418 to Birkofer.
Electrolytes such as sodium and ammonium chloride are known to raise the viscosity of surfactant formulations by increasing the size of the surfactant micelles. Long-chain lipophiles having a hydrophilic end-group such as alkanolamides, betaines and amine oxides are also known to increase viscosity by enlarging micelles.
U.S. Pat. No. 4,375,421 to Rubin, et al. discloses solutions containing alkylamido betaines and certain water-soluble inorganic and organic salts. These salts have a viscosity-building effect on aqueous compositions containing alkylamido betaines in the presence of anionic surfactants.
U.S. Pat. No. 4,490,355 to Desai teaches that a mixture of cocoamidopropyl betaine and oleamidopropyl betaine improves the thickening and foam boosting properties in hair and skin care formulations.
The viscosity enhancing effect of different amides on a 15% active monoethanolamine-lauryl sulfate and a 15% active sodium laureth-2 sulfate has been reported. B. R. Donaldson and E. T. Messenger, Int. J. Cosm. Sci. 1:71-90 (1979). In a different report, cocamide MEA was found to be an effective thickener, G. Felletschin, Tenside Detergents 7:16-18 (1970). Further, U. K. Patent Application No. GB 2 143 841A discloses the use of a variety of thickeners, including long-chain (C.sub.12 -C.sub.18) fatty acid amides, in thickened aqueous surfactant compositions.
It has also been proposed to thicken shampoos by combining two surfactants, one being a nonionic surfactant typified by dibasic and tribasic acid reaction products of alkoxylated polyol fatty esters and another being of a different type such as an amphoteric/anionic surfactant. U.S. Pat. No. 4,261,851 to Duke reports that the nonionic surfactant has a thickening effect on the composition.
A composition which exhibits improved viscosity enhancing properties over related compositions and which exhibits improved properties over conventional ethanolamides would be a desirable advance in the art.
Applicant has discovered that polyether amide derivatives made from water-soluble polyether amines and fatty acids exhibit outstanding properties compared with conventional ethanolamines in thickening and in compatibility with anionic surfactants. They also exhibit improved phase stability.
The fatty amides are preferably prepared from JEFFAMINE.RTM. ED-series amines and fatty acids or triglycerides or simple fatty esters such as tallow, oleic, tall oil, coconut, palm or linoleic.